22 | BA-40100-02-V17
TOPAX
®
DX
Multichannel controller
5.4 Temperature measurement input
5.4.1 Technical data
Power output
Values
Sensor
Pt 100
Measuring range:
-50°C ... +150°C
Measuring
accuracy
1 %
Do not use other than a two-wire "Pt 100" as sensor.
5.4.2 Calibration
The zero point of the measuring input is set in the factory. This meas-
uring input can be adjusted with the temperature of the measuring wa-
ter of the TOPAX DX (see chapter “19.1.4 Menu 1.2: Calibration” on
page 31).
To do this, measure the temperature of the sample water with a refer-
ence thermometer and set the reading as a reference in the TOPAX DX.
5.5 Measurement input total chlorine and display of
bonded chlorine
5.5.1 Technical data
Power output
Values
Sensor
Total chlorine measuring cell (encapsulated electrode)
Measuring signal
4 … 20 mA corresponding measuring range of the
measuring electrode
Measuring
accuracy
1 % after calibration
5.5.2 Calibration
The total chlorine measurement is pH and temperature-compensated.
For the measurement of the free chlorine the potentiostatic measuring
cell is necessary, otherwise a total chlorine measurement is not possi-
ble. In connection with the total chlorine measurement and the meas-
urement of free chlorine is displayed in the TOPAX DX.
You can continue to use the total chlorine for control. If you do so howev-
er, the total chlorine measurement will not be compensated.
Measurements of bonded chlorine are performed using and encapsulat-
ed electrode. This total chlorine measuring cell consists of a sensor part
with integrated electronics and supplies a 4 … 20 mA measuring signal
according to the measuring range 0.00-2.00 mg/l. The measuring cell
must be calibrated.
Calibration method: DPD
The sensor is operated with sample water. A nearly stable physical value
should be displayed. In order to avoid signal variations and consequent
reading errors, water must be taken at the sensing element and the
actual signal must be saved directly in the TOPAX DX upon taking of the
water sample. By means of the DPD method the total chlorine content
in the measuring water is determined. The measurement must be set in
the controller and saved by pressing OK. The measuring cell transcon-
ductance is then displayed. The plausibility of the transconductance
measurement is monitored throughout the process.
For the announcement of bound chlorine at the TOPAX DX it is nec-
essary that the total chlorine and the free chlorine, the pH value and
the temperature of the measuring water with the same TOPAX DX are
measured.
5.6 Conductivity measurement input
5.6.1 Technical data
Power output
Values
Sensor
conductive or inductive conductivity electrode with
measurement amplifier
Measuring signal
4...20 mA corresponding measuring range of the
measuring amplifier
Measuring
accuracy
± 1 % after calibration
As there is a growing trend towards brine or seawater pools, the brine
quality must be recorded. If an electrolytic cell, e.g. from Technopool, is
used to generate the free chlorine concentration, brine water must be
available as a precondition.
The conductivity of the measuring water can be measured and the con-
centration be kept constant. The measuring signal is converted into a
standard 4...20 mA current signal by a separate measuring amplifier.
5.6.2 Calibration
The sensor input requires adjustment (see section “19.1.4 Menu 1.2:
Calibration” on page 31). The zero point does not need to be adjusted.
Only the reference value is to be examined and adjusted if necessary.
The measuring cell transconductance is then displayed. The plausibil-
ity of the transconductance measurement is monitored throughout the
process.
The measurement is computationally shown as a % of salt content and
in mS/cm. Example: 4...20 mA corresponding 0...20 mS/cm.
current (mA)
salt content (mS/cm)
salt content (%)
4.00
0
0.00
4.80
1.0
0.05
5.60
2.0
0.10
6.40
3.0
0.15
7.20
4.0
0.20
8.00
5.0
0.25
8.80
6.0
0.30
9.60
7.0
0.35
10.40
8.0
0.40
11.20
9.0
0.45
12.00
10.0
0.50
12.80
11.0
0.55
13.60
12.0
0.60
14.40
13.0
0.65
15.20
14.0
0.70
16.00
15.0
0.75
16.80
16.0
0.80
17.60
17.0
0.85
18.40
18.0
0.90
19.20
19.0
0.95
20.00
20.0
1.00
